This invention relates generally to door knob/lever assemblies, and more particularly to improved knob/lever trim attachment and methods to provide an easily assembled and manufactured, aesthetically pleasing, and easily replaceable assembly.
In the art of door handle knob/lever assemblies, a hollow shaft is rotatably mounted within a door preparation in the well-known fashion by a housing attached to the door by screw fasteners. A door handle, and typically, a doorknob or lever, is mounted on the shaft by any of several mounting techniques. One or more set screws are used to secure the doorknob to the shaft. Problems with this technique include that the screw head is typically visible creating an aesthetically unpleasing surface. Special tools, such as an Allen wrench, may also be required to install and remove the doorknob. During operational life of the knob the screw can become loose, thus resulting in wobble, preventing proper operation of the door handle, or causing the handle to fall off when grasped by the user.
Another mechanical mounting technique stakes material in the reduced neck of the knob into openings formed in the shaft. This also axially locks the doorknob to the shaft while enabling the shaft to rotate when rotating the doorknob. However, this method is more of a permanent attachment technique and generally requires special knowledge and tools for removal.
In another mounting technique, the doorknob has a cylindrical, reduced neck portion which is slidably received over the shaft. The shaft has a radially projecting pin which is spring biased outwardly beyond the outer surface of the shaft. The pin is retracted by pressing it inwardly. The shaft receives the cylindrical portion of the door knob thereover, the cylindrical portion having an aperture formed therein which is sized to receive the pin of the shaft therethrough. The arrangement is such that by pressing the pin inwardly to its retracted position, sliding the cylindrical portion of the door knob over the pin, and aligning the aperture with the pin, the pin can extend through the aperture for axially and rotatably locking the door knob to the shaft. The pin method, however, generally requires that the complete handle assembly be disassembled in order to retract the pin and remove the knob. In addition, the pin method provides a relatively poor bearing support which generally allows a certain amount of rotational play and can also result in wobble.
Once secured to the shaft, the doorknob and shaft are rotatably mounted within an opening formed in the housing. In typical door assembly constructions there is a certain amount of wobble between the doorknob and shaft and the housing. This wobble is attributable to tolerances between the shaft and the opening of the housing, and the axial space between the housing and the doorknob.
From the foregoing, the limitations of known trim attachment methods include possible accidental or eventual pull of the trim (lever/knob) by the user which could cause injury. Any wobble or looseness of the trim also suggests inferior quality. Further, if replacement of the trim is desired, the user is faced with a difficult task requiring special knowledge of the construction, or the user must have special tools therefore. Typical trim attachments also degrade from the appearance of the trim or require removal of the lock from the door. Other disadvantages are also apparent in known attachment methods and trim assemblies.
The foregoing illustrates limitations known to exist in present handle/door knob designs. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.
It is an object of the present invention to provide an improved knob/lever trim attachment and method to allow easy assembly and manufacture, and to provide an aesthetically pleasing, and easily replaceable trim assembly. It is a further object of the present invention to provide an improved knob/lever trim attachment and method which prevents wobble between the knob/lever trim and the doorknob shaft, as well as improving resistance to torque upon rotation thereof.
In one aspect of the present invention, this is accomplished by providing a door handle/knob assembly comprising a spindle housing having a first end and a second end, wherein the first end comprises a spindle and the second end comprises a mechanism for engagement to a door lock assembly. The door lever/knob assembly further comprises a door knob having a handle portion and a neck portion, wherein the neck portion comprises a recess and a housing for a mechanism to retain the door knob on the spindle, and a mechanism for preventing relative rotation of the handle portion in relation to the spindle portion. In another aspect of the present invention, there is provided a method of attaching a door lever/knob to a door lock assembly comprising the steps of aligning a recess of the neck portion of the door lever/knob with a spindle portion of the door lock assembly, sliding the recess over the spindle portion, and automatically engaging a mechanism for retaining the door knob on the spindle. A method or detaching a door lever/knob from a door lock assembly is also provided.